Referring to FIG. 6, a conventional display device 300 includes four types of sub-pixels emitting different colors. There is a plurality of red sub-pixels 11, a plurality of green sub-pixels 12, a plurality of blue sub-pixels 13, and a plurality of white sub-pixels 14, wherein ratio of the complete red sub-pixels 11, the complete green sub-pixels 12, the blue sub-pixels 13 and the complete white sub-pixels 14 is 2:2:1:1. The display device 300 defines a plurality of pixel units 20. Each pixel unit 20 includes three sub-pixels each of which emitting a different color. The pixel unit 20 includes two different types. One kind of pixel unit 20a includes one red sub-pixel 11, one green sub-pixel 12, and one blue sub-pixel 13 arranged adjacent to each other. The other kind of pixel unit 20b includes one red sub-pixel 11, one green sub-pixel 12, and one complete white sub-pixel 14 arranged adjacent to each other. The pixel units 20a and the pixel units 20b are alternately arranged in a same row and in a same column. However, image artifacts may be introduced due to the poor symmetry between the blue sub-pixel 13 and the white sub-pixel 14 in adjacent pixel units 20. Therefore, there is room for improvement in the art.